1. Field of the Invention
The present invention relates to processors for video signals, and in particular, to video signal processors in which processing of video signals originating from a film scanner or a video storage device is controlled via a computerized interactive menu-driven operator control interface.
2. Description of the Related Art
Conventional film scanners and color correction systems, such as telecines, are well known and widely used. A light source is used to illuminate a film frame, thereby producing an optical film image. The optical film image is color filtered to separate the polychromatic optical film image into its constituent monochromatic optical film images. For example, red, green and blue color filters are typically used to separate the polychromatic optical film image into red, green and blue optical film images for independent or individual processing. Each of these red, green and blue optical film images is projected onto a photosensor, i.e. "imager," for conversion into electronic red, green and blue video color signals. These video color signals may then each be processed (e.g. color corrected), recorded onto a recording medium such as a tape or disk, and subsequently recombined to reproduce a polychromatic video image.
In processing the video image signals, scanning the film or reproducing the recorded video image signals, numerous controls and adjustments must be exercised. For example, video image signal processing, such as color processing or manipulation, often requires that specific features or characteristics of the video image signals, such as color saturation or hue, be precisely manipulated on a local or global scale. Further, it is often desirable to scan the film or reproduce prerecorded video image signals repeatedly or at different speeds to make interactive corrections or modifications to produce alternative images.
To do any of the foregoing, it is necessary to somehow control the devices which produce, process or reproduce the film or image signals, i.e. the scanner, processor and video storage device. Such control is generally exercised by directly manipulating hardware oriented controls, such as levers, buttons, dials or joysticks. However, these types of controls are generally electromechanical in nature and not as precise or accurate as would otherwise be desired. Thus, it is difficult to precisely and accurately process, produce or reproduce a specific portion of a film or video image signal. Further, it is difficult to alter or manipulate specific features or characteristics of a video image signal, such as a selected portion of its color space, or to cue the film or video image signal to a specific point.
Some computerized systems have been developed, but are limited in what they can do with respect to controlling the processing of video signals. For example, one system provides a computerized status monitor which provides the operator with textual information regarding status of various film or video parameters. Another system provides software for emulating the controls of a video tape recorder on a display screen. However, neither system provides for complete and direct control over the video signal processing or cuing.